Manual Merge 201756 "Changes how to compute the id of a display." (2nd)

ash/display/display_change_observer_x11.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/display/display_change_observer_x11.h"
 
 #include <algorithm>
 #include <map>
 #include <set>
 #include <vector>
 
 #include <X11/extensions/Xrandr.h>
 
 #include "ash/display/display_controller.h"
 #include "ash/display/display_info.h"
 #include "ash/display/display_manager.h"
 #include "ash/shell.h"
+#include "base/hash.h"
 #include "base/message_pump_aurax11.h"
 #include "grit/ash_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/x/x11_util.h"
 #include "ui/compositor/dip_util.h"
 #include "ui/gfx/display.h"
 
 namespace ash {
 namespace internal {
 
@@ skipping 49 matching lines @@
 }
 
 std::string GetDisplayName(XID output_id) {
   std::string display_name;
   ui::GetOutputDeviceData(output_id, NULL, NULL, &display_name);
   return display_name;
 }
 
 int64 GetDisplayId(XID output_id, int output_index) {
   uint16 manufacturer_id = 0;
-  uint16 product_code = 0;
-  if (ui::GetOutputDeviceData(
-          output_id, &manufacturer_id, &product_code, NULL) &&
-      manufacturer_id != 0) {
+  std::string product_name;
+
+  // ui::GetOutputDeviceData fails if it doesn't have product_name.
+  ui::GetOutputDeviceData(output_id, &manufacturer_id, NULL, &product_name);
+
+  // Generates product specific value from product_name instead of product code.
+  // See crbug.com/240341
+  uint32 product_code_hash = product_name.empty() ?
+      0 : base::Hash(product_name);
+  if (manufacturer_id != 0) {
     // An ID based on display's index will be assigned later if this call
     // fails.
-    return gfx::Display::GetID(manufacturer_id, product_code, output_index);
+    return gfx::Display::GetID(
+        manufacturer_id, product_code_hash, output_index);
   }
   return gfx::Display::kInvalidDisplayID;
 }
 
 }  // namespace
 
 DisplayChangeObserverX11::DisplayChangeObserverX11()
     : xdisplay_(base::MessagePumpAuraX11::GetDefaultXDisplay()),
       x_root_window_(DefaultRootWindow(xdisplay_)),
       xrandr_event_base_(0) {
@@ skipping 124 matching lines @@
 void DisplayChangeObserverX11::OnAppTerminating() {
 #if defined(USE_ASH)
   // Stop handling display configuration events once the shutdown
   // process starts. crbug.com/177014.
   Shell::GetInstance()->output_configurator()->Stop();
 #endif
 }
 
 }  // namespace internal
 }  // namespace ash